The present invention relates to a process for separating floc in a liquid and for accomplishing the sedimentation of the floc and an apparatus for carrying out the same. More particularly the invention relates to a process for accomplishing the sedimentation of the floc wherein a plurality of partition chambers comprising of a plurality of separate plates and a plurality of fins, have a narrow gap, so that the floc suspended in the mother liquid is caught in an eddy current occurring in the partition chamber while the floc is swirling downwardly in the partition chamber and the floating floc accumulates by contacting each other.
Prior Japanese patent publication No. 6663/1975 entitled "Floc Separating Apparatus" discloses features in which, the apparatus for separating solid from liquid includes a passage of mixture to be separated by arranging thin plates at proper intervals in parallel with each other and a pocket formed by protruding a fin from each thin plate in the passage. The improvement provides for the passage to be kept in a substantially horizontal condition to the weight direction by forming in many steps of thin plates. The pocket has an opening at the upper end arranged vertically to the flowing direction with fins on the partition wall by hanging down the fins on the upper surface only of the thin plates. And, the object thereof is to provide a plurality of fins hitting the liquid against the passage of separating layer in the settling tank thereby providing a change in the flowing condition of moving mother liquid with suspended floc therein to accomplish the sedimentation and separation in different conditions from the prior by providing a local stationary region. Thus, according to the publication, there is an advantage of reducing the size of the settling tank by increasing the catching effect of fine floc in the arrangement in the rear portion in the settling tank.
However, it should be understood that there is a disadvantage of ineffective results due to the accumulation and sticking of impurities in the liquid. A large amount of floating materials occur. The floc caught by the eddy current results from erect fins so that when the floc is separated in a downward sliding action on the oblique plate having a plurality of fins, separation is not carried out effectively due to the floating materials. It has therefore been found that a desired separating effect cannot be obtained even though the separating partition chamber is vertically provided in the beginning step of separation.